Catheter-associated bloodstream infection in patients with cancer: comparison of left- and right-sided insertions.

BACKGROUND: There is limited research on the relationship between side of insertion of central venous catheter (CVAD) and bloodstream infection risk in patients with cancer. AIM: To conduct an exploratory analysis of data from a randomized control trial (RCT) and data from a prospective cohort study to compare infection rates for right- and left-sided insertions. METHODS: The study populations were patients aged >14 years with cancer from two tertiary hospitals in Brisbane, Australia. The primary endpoint was catheter-associated bloodstream infection (CABSI) adjudicated by blinded assessors. For the RCT, randomized intention-to-treat comparisons were conducted between left- and right-side allocated insertion for early (≤14 days) and late (>14 days) infection using Cox proportional hazards regression. The RCT data were also combined with cohort study data collected from one of the hospitals prior to the RCT and non-randomized comparisons conducted between left- and right-sided insertions. FINDINGS: In 634 randomly allocated CVADs there were 141 CABSIs. Analysis showed strong evidence of right-side allocated insertions having an increased risk of early infection by 2.5 times (95% confidence interval (CI): 1.3-4.7); however, there was no evidence of increased risk for late infection (hazard ratio: 1.06; 95% CI: 0.71-1.59). Results from analysis of the RCT and cohort study data combined (2786 CVADs and 385 CABSIs) were similar. CONCLUSION: There appears to be an increased risk of CABSI in patients with cancer for CVAD inserted into the right-side for around two weeks after line insertion. The mechanism underpinning the increased risk is unknown.

Association Between Minimum Inhibitory Concentration, Beta-lactamase Genes and Mortality for Patients Treated With Piperacillin/Tazobactam or Meropenem From the MERINO Study.

INTRODUCTION: This study aims to assess the association of piperacillin/tazobactam and meropenem minimum inhibitory concentration (MIC) and beta-lactam resistance genes with mortality in the MERINO trial. METHODS: Blood culture isolates from enrolled patients were tested by broth microdilution and whole genome sequencing at a central laboratory. Multivariate logistic regression was performed to account for confounders. Absolute risk increase for 30-day mortality between treatment groups was calculated for the primary analysis (PA) and the microbiologic assessable (MA) populations. RESULTS: In total, 320 isolates from 379 enrolled patients were available with susceptibility to piperacillin/tazobactam 94% and meropenem 100%. The piperacillin/tazobactam nonsusceptible breakpoint (MIC >16 mg/L) best predicted 30-day mortality after accounting for confounders (odds ratio 14.9, 95% confidence interval [CI] 2.8-87.2). The absolute risk increase for 30-day mortality for patients treated with piperacillin/tazobactam compared with meropenem was 9% (95% CI 3%-15%) and 8% (95% CI 2%-15%) for the original PA population and the post hoc MA populations, which reduced to 5% (95% CI -1% to 10%) after excluding strains with piperacillin/tazobactam MIC values >16 mg/L. Isolates coharboring extended spectrum ß-lactamase (ESBL) and OXA-1 genes were associated with elevated piperacillin/tazobactam MICs and the highest risk increase in 30-day mortality of 14% (95% CI 2%-28%). CONCLUSIONS: After excluding nonsusceptible strains, the 30-day mortality difference from the MERINO trial was less pronounced for piperacillin/tazobactam. Poor reliability in susceptibility testing performance for piperacillin/tazobactam and the high prevalence of OXA coharboring ESBLs suggests that meropenem remains the preferred choice for definitive treatment of ceftriaxone nonsusceptible Escherichia coli and Klebsiella.

Does copper treatment of commonly touched surfaces reduce healthcare-acquired infections? A systematic review and meta-analysis.

BACKGROUND: Healthcare-acquired infections (HAIs) cause substantial morbidity and mortality. Copper appears to have strong antimicrobial properties under laboratory conditions. AIM: To examine the potential effect of copper treatment of commonly touched surfaces in healthcare facilities. METHODS: Controlled trials comparing the effect of copper-treated surfaces (furniture or bed linens) in hospital rooms compared with standard rooms on HAIs were included in this systematic review. Two reviewers independently screened retrieved articles, extracted data, and assessed the risk of bias of included studies. The primary outcome was the occurrence of HAIs. FINDINGS: In total, 638 records were screened, and seven studies comprising 12,362 patients were included. All included studies were judged to be at high risk of bias in two or more of the seven domains. All seven studies reported the effect of various copper-treated surfaces on HAIs. Overall, this review found low-quality evidence of potential clinical importance that copper-treated hard surfaces and/or bed linens and clothes reduced HAIs by 27% (risk ratio 0.73, 95% confidence interval 0.57-0.94; I2 = 44%, P=0.01). CONCLUSION: Given the clinical and economic costs of HAIs, the potentially protective effect of copper treatment appears to be important. The current evidence is insufficient to make a strong positive recommendation. However, it would appear worthwhile and urgent to conduct larger publicly funded clinical trials into the impact of copper treatment.

Catheter-associated bloodstream infections in adults with cancer: a prospective randomized controlled trial.

BACKGROUND: A common complication of central venous access devices (CVADs) is catheter-associated bloodstream infection (CABSI). We previously demonstrated that insertion of CVADs on the right side was associated with increased risk of CABSI, and hypothesized that this related to the predominance of right-handedness in the patient population, resulting in greater movement and bacterial contamination. AIM: To perform a prospective randomized, controlled, non-blinded study to determine whether the side of CVAD insertion influenced the incidence of CABSI. METHODS: Adult cancer patients were randomly allocated to either dominant or non-dominant side CVAD insertion. The primary endpoint of the study was the number of line-days until CABSI, determined in a blinded fashion by two assessors. FINDINGS: In all, 640 CVADs were randomized to dominant (N = 322) or non-dominant (N = 318) side of insertion, 60% had haematological malignancies, and 40% solid tumours. CVADs were a peripherally inserted central catheter line (67%), tunnelled CVAD (23%), and non-tunnelled CVAD (10%). Twenty-two percent of CVADs were complicated by CABSI. The rate of CABSI per 1000 line-days was 3.49 vs 3.66 in the non-dominant vs dominant group (hazard ratio (HR): 0.91; 95% confidence interval (CI): 0.65-1.28). By multivariable analysis, the rate of CABSI was increased by: use of tunnelled CVADs compared to peripherally inserted central venous catheter lines (HR: 2.05; 95% CI: 1.45-2.91); having a haematological malignancy compared to non-gastrointestinal solid tumours (5.55; 2.47-12.5); but not dominant compared to non-dominant side of CVAD (0.97; 0.69-1.36). CONCLUSION: CABSI in adult patients with cancer was not impacted by whether CVAD insertion was on the dominant or non-dominant side.

Supervised self-administration of outpatient parenteral antibiotic therapy: a report from a large tertiary hospital in Australia.

INTRODUCTION: Outpatient parenteral antibiotic therapy (OPAT) has become established as a standard of care in most Australian hospitals to treat a variety of infections. Since 1998, the Alternate Site Infusion Service (ASIS) has provided an OPAT service to five hospitals in southern Brisbane, Queensland, using predominantly a patient or carer administration model (self-administered, S-OPAT). The aim of this study was to evaluate outcomes of our S-OPAT programme. METHODS: Consecutive patients treated by ASIS at the Princess Alexandra Hospital from January 1, 2011 to December 31, 2011 were reviewed. Data on patient demographics, diagnoses, microbiology, antimicrobial therapy, duration, outcome, and complications were sourced from a prospectively collected database and from patient medical records. RESULTS: There were 150 episodes involving 144 patients resulting in 3520 days of OPAT; the median duration on the programme was 22 days (range 4­106 days). Patient or carer administration occurred in the majority of episodes. The most common indication by far was bone or joint infection (47% of patients), followed by infective endocarditis (9%). Staphylococcus aureus was the most frequently treated organism. The overall cure rate was 93%. On multivariate analysis, patients with two or more comorbidities had an increased risk of failure. Line-related complications occurred in 1.4/1000 catheter-days. Rash was the most common drug-related event. Despite the extensive use of broad-spectrum antibiotics there were no cases of Clostridium difficile infection during therapy and for up to 28 days post cessation of intravenous antibiotics. The cost of OPAT per patient excluding drug administration and home visits was approximately A$ 150.00/day, significantly lower than the cost of an inpatient bed, which is estimated to be A$ 500­800/day.5 CONCLUSION: OPAT using a patient or carer administration model is an effective and safe option for the management of selected patients with infection requiring intravenous antibiotics.

Infectious diseases consultations at an Australian tertiary hospital: a review of 11,511 inpatient consultations.

BACKGROUND: Infectious diseases (ID) clinicians provide an important service within tertiary hospitals. However, as a largely consultation-based service, their value can be difficult to evaluate. AIMS: A review of 13.5 years of consultations was undertaken to define the scope of the service and any changes over time. METHODS: ID consultations at the Princess Alexandra Hospital are tracked on a database, recording information including the requesting team, indication for and outcome of the consult. Incident formal inpatient consultations between July 1999 and December 2012 were reviewed retrospectively. Phone consultations, repeat consultations and ID admissions were excluded. RESULTS: Eleven thousand five hundred and eleven consultations were identified, with annual consultations increasing significantly during this period. Overall, formal consultations were performed on 1.3% of admissions. Consultations were most commonly requested by orthopaedics (14.3%) and general medicine (11.4%). The two most common syndromes triggering a consult were bloodstream infection (13.9%) and complicated soft tissue infection (7.8%). The final diagnosis was most frequently osteomyelitis (7.9%). Staphylococcus aureus (19.4%) and Pseudomonas aeruginosa (8.3%) were the most commonly identified pathogens. CONCLUSION: The demand for ID consultations has increased over time and there are likely to be many drivers of this increase. Information derived from this audit can enhance the ID service by guiding service delivery, trainee education and informing funding or accreditation applications.

Catheter-associated bloodstream infection incidence and risk factors in adults with cancer: a prospective cohort study.

Central venous catheter-associated bloodstream infections (CABSIs) cause considerable morbidity in patients with cancer. We determined the incidence and risk factors for CABSI by performing a prospective observational cohort study of all adult patients requiring a central venous access device (CVAD) in a haematology-oncology unit. All CVADs were inserted under ultrasound guidance by trained operators in a dedicated interventional radiology facility. A total of 1127 CVADs were assessed in 727 patients over 51,514 line-days. The rate of CABSI per 1000 line-days was 2.50. Factors associated with CABSI included: type of CVAD, greatest for non-tunnelled lines [hazard ratio (HR): 3.50; P < 0.0001] and tunnelled lines (HR: 1.77; P = 0.011) compared to peripherally inserted central venous catheter (PICC) lines; patient diagnosis, greatest for aggressive haematological malignancies (HR: 3.17; P = 0.0007) and least for oesophageal, colon and rectal cancers (HR: 0.29; P = 0.019) compared to other solid tumours; side of insertion, greatest for right-sided lines (HR: 1.60; P = 0.027); and number of prior line insertions (HR: 1.20; P = 0.022). In patients with aggressive haematological malignancies there was significantly more CABSI with non-tunnelled lines (HR: 3.9; P < 0.001) and a trend to more CABSI with tunnelled lines (HR: 1.43; P = 0.12) compared to patients with PICC lines, as well as increased CABSI for right-sided insertions (HR: 1.62; P = 0.047). This study highlights the utility of a standardised CABSI surveillance strategy in adult patients with cancer, provides further data to support the use of PICC lines in such patient populations, and suggests that the side of line insertion may influence risk of CABSI.

Sequential analysis of uncommon adverse outcomes.

Sequential analysis of uncommon adverse outcomes (AEs) such as surgical site infections (SSIs) is desirable. Short postoperative lengths of stay (LOS) result in many SSIs occurring after discharge and they are often superficial. Deep and organ space (complex) SSIs occur less frequently but are detected more reliably and are suitable for monitoring wound care. Those occurring post-discharge usually require readmissison and can be counted accurately. Sequential analysis of meticillin-resistant Staphylococcus aureus bacteraemia is also needed. The key to prevention is to implement systems based on evidence, e.g. using 'bundles' and checklists. Regular mortality and morbidity audit meetings are required and these may need to be followed by independent audits. Sequential statistical analysis is desirable for data presentation, to detect changes, and to discourage tampering with processes when occasional AEs occur in a reliable system. Tabulations and cumulative observed minus expected (O-E) charts and funnel plots are valuable, supplemented in the presence of apparent 'runs' of AEs by cumulative sum analysis. Used prospectively, they may enable staff to visualise and detect patterns or shifts in rates and counts that might not otherwise be apparent.

Changes in serum procalcitonin and C-reactive protein following antimicrobial therapy as a guide to antibiotic duration in the critically ill: a prospective evaluation.

Serial procalcitonin is reported to be useful to titrate duration of antibiotic therapy in the non critically ill patient with pneumonia. The aim of this study was to examine the relationship between antibiotic therapy and serial serum procalcitonin concentrations in a cohort of critically ill septic patients and examine for any differences between culture positive (CP) and culture negative (CN) sepsis. Seventy-five critically ill patients with suspected sepsis were enrolled in this prospective observational study. Serial procalcitonin and C-reactive protein assays were measured on days one, three, five, seven, 10 and 14. The mean duration of antibiotic therapy was similar in the two groups (10.4 +/- 5.1 (CP) vs. 8.4 +/- 5.1 (CN) days, P = 0.09). Serum procalcitonin concentrations were significantly higher at baseline in the CP than the CN group (14.9 +/- 22.9 vs. 6.8 +/- 21.5 ng/ml, P = 0.04). During the study period, serum concentrations of procalcitonin and C-reactive protein declined in both groups. Serum procalcitonin consistently remained higher in the CP group (P < 0.05) and did not return to normal values. In the CN group, procalcitonin concentrations fell below 0.5 only on day 10. There was no significant difference in C-reactive protein profile between the two groups. Four patients in the CP group (11%) had relapse of sepsis. The mean procalcitonins in the relapsed subgroup were lower than those in the remission subgroup (P = 0.02). Therapy for proven or presumed infections was associated with declining serum procalcitonin and C-reactive protein in critically ill septic patients. The marked variability and overlap in plasma profile of these markers between CP and CN sepsis makes it difficult to define a nadir plasma concentration at which one can recommend discontinuation of antibiotic therapy.

Successful treatment of post-neurosurgical intracranial Mycoplasma hominis infection using gatifloxacin.

We describe two cases of intracerebral infection with Mycoplasma hominis following neurosurgery, the first after removal of a colloid cyst, the other after a craniotomy following a motor vehicle accident (MVA). Both infections were successfully treated with parenteral gatifloxacin, with ongoing clindamycin or moxifloxacin for associated osteomyelitis.

Cavernous sinus thrombosis and meningitis from community-acquired methicillin-resistant Staphylococcus aureus infection.

Septic cavernous sinus thrombosis is an uncommon clinical syndrome with a high morbidity and mortality. The commonest bacterial pathogen is Staphylococcus aureus. We describe the study of a patient with cavernous sinus thrombosis and meningitis caused by community-acquired methicillin-resistant S. aureus (CA-MRSA) infection. The isolate was genotyped as the ST93 (Queensland) clone of CA-MRSA and carried the Panton-Valentine leucocidin genes. Cure was obtained following prolonged antimicrobial therapy with vancomycin, rifampicin, cotrimoxazole and linezolid. Given the high morbidity and mortality of cavernous sinus thrombosis and the worldwide recent emergence of CA-MRSA, clinicians treating patients with this infection should consider early empirical coverage for CA-MRSA with an antimicrobial agent, such as vancomycin or linezolid, particularly in the presence of suspected facial staphylococcal skin infections. If vancomycin is used, we emphasize that high doses may be required to achieve even low levels in the cerebrospinal fluid.

Post-discharge surveillance: can patients reliably diagnose surgical wound infections?

Post-discharge surgical wound infection surveillance is an important part of many infection control programs. It is frequently undertaken by patient self-assessment, prompted either by a telephone or postal questionnaire. To assess the reliability of this method, 290 patients were followed for six weeks postoperatively. Their wounds were photographed and also covertly assessed for signs of infection by two experienced infection control nurses (ICNs). Patients also responded to a postal questionnaire seeking evidence of infection at both week four and week six post-surgery. Correlation between the patient's assessment of their wound and the ICNs diagnosis was poor (r = 0.37) with a low positive predictive value (28.7%), although negative predictive value was high (98.2%). Assessment of photos for signs of infection by two experienced clinicians also correlated poorly with the ICNs diagnosis of infection (r = 0.54). The patient's recall of prescription of an antibiotic by their general practitioner (GP) for wound infection during the postoperative period correlated best with the ICNs diagnosis (r = 0.76). This latter measure, particularly when confirmed by the GP in those patients reporting an infection, appears to provide the most valid and resource efficient marker of post-discharge surgical wound infection.

Hypercalcaemia and elevated 1,25(OH)(2)D(3) levels associated with disseminated Mycobacterium avium infection in AIDS.

Hypercalcaemia may complicate granulomatous diseases, such as tuberculosis and sarcoidosis, and various AIDS-related opportunistic infections and malignancies. We report here two patients with AIDS and disseminated Mycobacterium avium infection who developed symptomatic hypercalcaemia several weeks after commencing antimycobacterial chemotherapy, and in whom inappropriately elevated 1,25(OH)(2)D(3)levels were documented. Although vitamin D supplementation may have contributed, no other cause for the hypercalcaemia was found. The biochemical and clinical similarities between these cases and other hypercalcaemic granulomatous diseases suggest a common mechanism related to macrophage activation and dysregulated vitamin D production.

The relationship of a clonal outbreak of Enterococcus faecium vanA to methicillin-resistant Staphylococcus aureus incidence in an Australian hospital.

Australian isolates of vancomycin-resistant enterococci (VRE) have been widely scattered geographically, predominantly polyclonal and of the VanB phenotype. Forty-nine VRE were isolated from 47 patients in our hospital from October 1996 to December 1999. Forty-four of these VRE were Enterococcus faecium with a vanA glycopeptide resistance genotype. Four isolates were pathogenic. Thirty-five VRE were from an outbreak in the Renal and Infectious Diseases Units over a four-month period. Pulsed-field gel electrophoresis (PFGE) demonstrated that 41 of the 49 VRE were indistinguishable or closely related. Enhanced environmental cleaning, strict contact isolation of colonized patients and reducing inpatient admissions terminated the epidemic. Cohorting of methicillin-resistant Staphylococcus aureus (MRSA)-positive patients was restricted because VRE patients occupied the isolation facilities. This resulted in a statistically significant increase in MRSA infections across the hospital. VRE epidemics have the ability to influence the epidemiology of other nosocomial pathogens when infection control resources are exhausted.

The application of statistical process control charts to the detection and monitoring of hospital-acquired infections.

The monitoring of infection control indicators including hospital-acquired infections is an established part of quality maintenance programmes in many health-care facilities. However, surveillance data use can be frustrated by the infrequent nature of many infections. Traditional methods of analysis often provide delayed identification of increasing infection occurrence, placing patients at preventable risk. The application of Shewhart, Cumulative Sum (CUSUM) and Exponentially Weighted Moving Average (EWMA) statistical process control charts to the monitoring of indicator infections allows continuous real-time assessment. The Shewhart chart will detect large changes, while CUSUM and EWMA methods are more suited to recognition of small to moderate sustained change. When used together, Shewhart and EWMA methods are ideal for monitoring bacteraemia and multiresistant organism rates. Shewhart and CUSUM charts are suitable for surgical infection surveillance.

Endemic nosocomial gram-negative bacteraemias resulting from contamination of intravenous heparin infusions.

Following several cases of Gram-negative bacteraemia secondary to intravenous heparin infusion contamination, we retrospectively reviewed nosocomial bacteraemias associated with heparin infusions at our institution. Thirty-one episodes of heparin-infusion related bacteraemia occurred in 30 patients over a 23-month period affecting 2% patients receiving heparin infusions for more than 48 h. Gram-negative bacteria were responsible for all bacteraemias. The care of infusions during clinical use was prospectively surveyed, revealing that approximately 20% of lines and cannulae were left for more than 72 h before replacement, and significant discordance occurred between line replacement and syringe and cannula exchange. We concluded that contamination of the infusions was probably extrinsic and secondary to manipulations of the system during use. Prolonged usage and discordant exchange of infusion components were likely important factors in initial contamination and subsequent bacterial proliferation. The problem resolved following the introduction of a policy for routine and simultaneous replacement of lines and syringes at 24-h intervals and upon cannula exchange.